Machine tool holders used for grinding, cutting and shaping workpieces have been made in a single piece construction. However, it is often time consuming and expensive to manufacture single piece tools.
As an alternative to single piece construction, it is known to manufacture the tool in two pieces and then weld corresponding faces of the two pieces together. Inertia welding is typically employed for this purpose wherein the corresponding faces are rotated in opposite directions against each other under severe pressure conditions so that the corresponding faces form a common weldment.
While such welding procedures effectively join the two tool pieces together, the procedure suffers from significant disadvantages. Specifically, inertia welding typically results in the entrapment of gases in the welded area which often leads to stress fractures and consequential tool failure. In addition, it is very difficult to machine such welds which results in significant limitations on the design of the tool.
There have been efforts to join two components of a machine tool together by methods other than welding. One such effort has been to design a tool with one component of the tool having a male projection which fits into a female cavity of the second component. Screw receiving spaces are provided at opposite sides and perpendicular to the longitudinal axis of the projection. Screws are inserted into the screw receiving spaces and turned to engage and force the tool components together.
Such methods have not been successful in providing a meaningful alternative to one piece construction and the welding of two components together. This is because the cavity and screw locking mechanism are not able to withstand the vibrational forces generated during use of the machine tool. This is due in part because such a locking mechanism provides only single line contact between the screw and the tool components and therefore is insufficient to effectively lock the two tool components together. In addition, the screws on each of the opposite sides of the projection are not locked in simultaneously. This results in less than a maximum locking force being applied to the locked tool components. Still further, there is no provision in such locked tools for alleviating the forces on the tool resulting from excessive vibration.
It is therefore an object of the invention to provide an encapsulated self-contained locking assembly by which components o a machine tool can be locked together simultaneously to maximize the locking force so that the tool is at least as strong as if it were made of a single piece construction.
It is another object of the invention to provide a locking assembly which joins the components of a machine tool together with full face to face contact of the locking members.
It is still another object of the invention to provide a locking assembly which eliminates axial misalignment and secures the components of the tool together under uniform pressure.
It is a further object of the invention to provide a machine tool component which dampens the vibrational forces acting on the tool during machining operations.